The current apparatus and technology for sealing gas mains as briefly described above is well known as may be seen by reference to some or all of the following:
U.s. pat. No. 3,141,478 PA1 U.s. pat. No. 3,178,793 PA1 U.s. pat. No. 3,228,146 PA1 U.s. pat. No. 3,260,280 PA1 U.s. pat. No. 3,265,782
Abandoned U.S. application of E. O. Hilbush Ser. No. 503,817 filed Oct. 23, 1965.
The sealing collars currently in use have proven to be unsatisfactory since they cannot withstand pressures greatly in excess of 3 psi in the gas mains. Also the sealant when forced through the inlet tube fails to flow evenly around the main, because one side or the other reaches the vent prematurely thus causing a gas pocket to be formed which thereby inhibits or prevents the proper sealing of the leaking joint.